The present invention relates to microporous films comprising flocked fibers, which provide a desirable, breathable material that may be used for example in absorbent articles, wound care products, and skin care products.
xe2x80x9cBreathablexe2x80x9d materials are those that allow gases but not liquids to pass through them. They have found advantageous application as breathable backsheets for products like absorbent articles, such as sanitary napkins and pantiliners. They are also employed in wound care products such as bandages that provide protection from dirt, germs, and water while maintaining an ideal environment for would healing.
Common breathable materials include polyurethane films, microporous films, and laminates of permeable films and nonwovens. Conventional microporous films are made by subjecting a film to ionizing radiation or by leaching out of soluble inclusions on the film using aqueous or nonaqueous solvents. Alternatively, microporous films are made by incorporating micron size particles into an extruded film, followed by controlled stretching of the film to create small voids in it. See for example, U.S. Pat. Nos. 4,923,650 and 5,126,391. However, microporous films by themselves are generally not soft feeling and do not mimic the texture of fabric very well. On the other hand, they have excellent resistance to strike through by liquids.
A variety of film/nonwoven laminates are also known to provide breathability. Such laminates advantageously have the attributes of a fabric. For example, U.S. Pat. No. 5,932,497 discloses a breathable film loaded with a filler and stretched in at least two directions laminated to a nonwoven web.
Flocking is a technique by which fibers are fixed in a vertical position on a substrate, and is primarily used in the fabric industry. However, EP 0 737 462 A1 discloses a laminated material to cover the outside of an absorbent product such as a sanitary napkin, characterized in that at least one portion of the surface of the laminated material bears a layer of fibers applied by flocking. The flocked fibers are thereby located on the external surface of the absorbent product in order to give the absorbent product improved tactile properties over products that employ plastic films against the skin.
It has now been discovered that a microporous film comprising flocked fibers may be made. Such a composite material provides good breathability with low liquid strike through. It may be used in absorbent articles, in particular as a backsheet on sanitary protection articles. It may also be used as a component of a wound care bandage or skin care patch. Surprisingly, the application of flocked fibers to a microporous film does not impair its overall breathability. At the same time, the microporous film is endowed with a soft surface. The flocking also provides a vehicle for holding additives like moisturizers, medicaments, and the like on the microporous film.
The invention provides a microporous film comprising flocked fibers, as well as an absorbent article, wound care bandage, or skin care patch comprising such a microporous film.